Field of Invention
The present invention relates to a method and apparatus for measuring the condensation amount in a flow of gas.
A seasonal variation in recorded performance of consistently constructed aircraft jet engines, together with variable amounts of condensate occurring in the engine intake apparatus during calibration, gives rise to a requirement to quantify the amount of water condensing in the intake apparatus. Condensation and subsequent re-evaporation in other parts of the engine is expected to affect the engine thermal cycle (by raising the temperature at which compression takes place) and other physical processes relating to the condensed fluid. Therefore condensation would appear to explain the seasonal variation in performance during engine calibration due to changing atmospheric conditions.
Condensation arises in the engine intake apparatus because of the high induced velocity causing a depressed air temperature as it enters the engine intake. The water content of the air, however, remains unchanged thereby increasing the relative humidity. With the high induced air velocity encountered on modern intakes the relative humidity may rise above 100% on some test occasions causing condensation and slightly decreasing the amount of temperature depression relative to simple dry air theory.
Condensation is not readily measured directly and is not open to reliable prediction without obtaining data concerning the numerical, physical and chemical composition of the local atmosphere. A new approach is therefore required.